/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright 2018 Philippe Proulx <pproulx@efficios.com>
 */

#include <babeltrace2/babeltrace.h>
#include "common/macros.h"
#include "common/assert.h"
#include "compat/glib.h"
#include <glib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <inttypes.h>
#include "common/assert.h"

#include "ctf-meta-visitors.hpp"

static void force_update_field_class_in_ir(struct ctf_field_class *fc, bool in_ir)
{
    uint64_t i;

    if (!fc) {
        goto end;
    }

    fc->in_ir = in_ir;

    switch (fc->type) {
    case CTF_FIELD_CLASS_TYPE_STRUCT:
    {
        struct ctf_field_class_struct *struct_fc = ctf_field_class_as_struct(fc);

        for (i = 0; i < struct_fc->members->len; i++) {
            struct ctf_named_field_class *named_fc =
                ctf_field_class_struct_borrow_member_by_index(struct_fc, i);

            force_update_field_class_in_ir(named_fc->fc, in_ir);
        }

        break;
    }
    case CTF_FIELD_CLASS_TYPE_VARIANT:
    {
        struct ctf_named_field_class *named_fc;
        struct ctf_field_class_variant *var_fc = ctf_field_class_as_variant(fc);

        for (i = 0; i < var_fc->options->len; i++) {
            named_fc = ctf_field_class_variant_borrow_option_by_index(var_fc, i);

            force_update_field_class_in_ir(named_fc->fc, in_ir);
        }

        break;
    }
    case CTF_FIELD_CLASS_TYPE_ARRAY:
    case CTF_FIELD_CLASS_TYPE_SEQUENCE:
    {
        struct ctf_field_class_array_base *array_fc = ctf_field_class_as_array_base(fc);

        force_update_field_class_in_ir(array_fc->elem_fc, in_ir);
        break;
    }
    default:
        break;
    }

end:
    return;
}

static void update_field_class_in_ir(struct ctf_field_class *fc, GHashTable *ft_dependents)
{
    int64_t i;

    if (!fc) {
        goto end;
    }

    switch (fc->type) {
    case CTF_FIELD_CLASS_TYPE_INT:
    case CTF_FIELD_CLASS_TYPE_ENUM:
    {
        struct ctf_field_class_int *int_fc = ctf_field_class_as_int(fc);

        /*
         * Conditions to be in trace IR; one of:
         *
         * 1. Does NOT have a mapped clock class AND does not
         *    have a special meaning.
         * 2. Another field class depends on it.
         */
        if ((!int_fc->mapped_clock_class && int_fc->meaning == CTF_FIELD_CLASS_MEANING_NONE) ||
            bt_g_hash_table_contains(ft_dependents, fc)) {
            fc->in_ir = true;
        }

        break;
    }
    case CTF_FIELD_CLASS_TYPE_STRUCT:
    {
        struct ctf_field_class_struct *struct_fc = ctf_field_class_as_struct(fc);

        /*
         * Make it part of IR if it's empty because it was
         * originally empty.
         */
        if (struct_fc->members->len == 0) {
            fc->in_ir = true;
        }

        /* Reverse order */
        for (i = (int64_t) struct_fc->members->len - 1; i >= 0; i--) {
            struct ctf_named_field_class *named_fc =
                ctf_field_class_struct_borrow_member_by_index(struct_fc, i);

            update_field_class_in_ir(named_fc->fc, ft_dependents);

            if (named_fc->fc->in_ir) {
                /* At least one member is part of IR */
                fc->in_ir = true;
            }
        }

        break;
    }
    case CTF_FIELD_CLASS_TYPE_VARIANT:
    {
        struct ctf_named_field_class *named_fc;
        struct ctf_field_class_variant *var_fc = ctf_field_class_as_variant(fc);

        /*
         * Reverse order, although it is not important for this
         * loop because a field class within a variant field
         * type's option cannot depend on a field class in
         * another option of the same variant field class.
         */
        for (i = (int64_t) var_fc->options->len - 1; i >= 0; i--) {
            named_fc = ctf_field_class_variant_borrow_option_by_index(var_fc, i);

            update_field_class_in_ir(named_fc->fc, ft_dependents);

            if (named_fc->fc->in_ir) {
                /* At least one option is part of IR */
                fc->in_ir = true;
            }
        }

        if (fc->in_ir) {
            /*
             * At least one option will make it to IR. In
             * this case, make all options part of IR
             * because the variant's tag could still select
             * (dynamically) a removed option. This can mean
             * having an empty structure as an option, for
             * example, but at least all the options are
             * selectable.
             */
            for (i = 0; i < var_fc->options->len; i++) {
                ctf_field_class_variant_borrow_option_by_index(var_fc, i)->fc->in_ir = true;
            }

            /*
             * This variant field class is part of IR and
             * depends on a tag field class (which must also
             * be part of IR).
             */
            g_hash_table_insert(ft_dependents, var_fc->tag_fc, var_fc->tag_fc);
        }

        break;
    }
    case CTF_FIELD_CLASS_TYPE_ARRAY:
    case CTF_FIELD_CLASS_TYPE_SEQUENCE:
    {
        struct ctf_field_class_array_base *array_fc = ctf_field_class_as_array_base(fc);

        update_field_class_in_ir(array_fc->elem_fc, ft_dependents);
        fc->in_ir = array_fc->elem_fc->in_ir;

        if (fc->type == CTF_FIELD_CLASS_TYPE_ARRAY) {
            struct ctf_field_class_array *arr_fc = ctf_field_class_as_array(fc);

            assert(arr_fc->meaning == CTF_FIELD_CLASS_MEANING_NONE ||
                   arr_fc->meaning == CTF_FIELD_CLASS_MEANING_UUID);

            /*
             * UUID field class: nothing depends on this, so
             * it's not part of IR.
             */
            if (arr_fc->meaning == CTF_FIELD_CLASS_MEANING_UUID) {
                fc->in_ir = false;
                array_fc->elem_fc->in_ir = false;
            }
        } else if (fc->type == CTF_FIELD_CLASS_TYPE_SEQUENCE) {
            if (fc->in_ir) {
                struct ctf_field_class_sequence *seq_fc = ctf_field_class_as_sequence(fc);

                /*
                 * This sequence field class is part of
                 * IR and depends on a length field class
                 * (which must also be part of IR).
                 */
                g_hash_table_insert(ft_dependents, seq_fc->length_fc, seq_fc->length_fc);
            }
        }

        break;
    }
    default:
        fc->in_ir = true;
        break;
    }

end:
    return;
}

/*
 * Scopes and field classes are processed in reverse order because we need
 * to know if a given integer field class has dependents (sequence or
 * variant field classes) when we reach it. Dependents can only be located
 * after the length/tag field class in the metadata tree.
 */
BT_HIDDEN
int ctf_trace_class_update_in_ir(struct ctf_trace_class *ctf_tc)
{
    int ret = 0;
    uint64_t i;

    GHashTable *ft_dependents = g_hash_table_new(g_direct_hash, g_direct_equal);

    BT_ASSERT(ft_dependents);

    for (i = 0; i < ctf_tc->stream_classes->len; i++) {
        ctf_stream_class *sc = (ctf_stream_class *) ctf_tc->stream_classes->pdata[i];
        uint64_t j;

        for (j = 0; j < sc->event_classes->len; j++) {
            ctf_event_class *ec = (ctf_event_class *) sc->event_classes->pdata[j];

            if (ec->is_translated) {
                continue;
            }

            update_field_class_in_ir(ec->payload_fc, ft_dependents);
            update_field_class_in_ir(ec->spec_context_fc, ft_dependents);
        }

        if (!sc->is_translated) {
            update_field_class_in_ir(sc->event_common_context_fc, ft_dependents);
            force_update_field_class_in_ir(sc->event_header_fc, false);
            update_field_class_in_ir(sc->packet_context_fc, ft_dependents);
        }
    }

    if (!ctf_tc->is_translated) {
        force_update_field_class_in_ir(ctf_tc->packet_header_fc, false);
    }

    g_hash_table_destroy(ft_dependents);
    return ret;
}
